1. Field of the Invention
The present invention relates to an electric door lock, more particularly to an electric door lock which is operable both manually and electrically.
2. Description of the Related Art
Electric door locks are known in the art. A conventional electric door lock generally includes an electric motor with a transmission shaft coupled to a spindle which is connected operably to a latch-bolt. By operating the electric motor, the spindle is rotated to move the latch-bolt between locking and unlocking positions. On the other hand, a conventional manually operable door lock is known to include a lock body having a manual operating portion and a key-operated lock unit which are operable for rotating a spindle, and a latch-bolt connected operably to the spindle. By operating the manual operating portion or by operating the lock unit with the corresponding key, the spindle can be rotated to move the latch-bolt between locking and unlocking positions.
In the aforementioned co-pending U.S. patent application Ser. No. 09/977,892, there is disclosed an electric door lock that is operable electrically and manually so as to provide added convenience to the user. The electric door lock includes a deadbolt mounted in a lock housing and movable between locking and unlocking positions. A manual operating member is mounted on the lock housing, and has a spindle that extends into the lock housing and that is connected operably to the deadbolt, and a manually operable rotary knob that is secured to one end of the spindle and that is disposed externally of the lock housing. A spindle coupling ring is sleeved on the spindle so as to be co-rotatable therewith. The spindle coupling ring has an annular outer peripheral surface formed with a plurality of angularly displaced first locking grooves. A rotary seat has a circular gear plate portion sleeved rotatably on the spindle, and an annular clutch portion connected fixedly and co-axially to the gear plate portion. The clutch portion is disposed around the spindle coupling ring, and has an inner surface confronting the spindle coupling ring, and an outer surface opposite to the inner surface. The clutch portion is formed with a plurality of mounting holes which are aligned respectively with the first locking grooves in the spindle coupling ring. Each of the mounting holes has an open inner hole end formed at the inner surface, and an open outer hole end formed at the outer surface. A stationary seat is disposed within and is secured to the lock housing. The stationary seat has a ring portion which is disposed around the clutch portion and which has an annular inner peripheral surface confronting the clutch portion. The inner peripheral surface is formed with a plurality of angularly displaced second locking grooves. The locking units are mounted respectively in the mounting holes, and each has a locking member with an inner locking portion disposed at the inner hole end of the respective mounting hole, and an outer locking portion disposed at the outer hole end of the respective mounting hole. The locking member is normally disposed in a first position, in which the outer locking portion of the locking member projects radially and outwardly from the outer surface of the clutch portion and engages a respective one of the second locking grooves in the stationary seat for locking the rotary seat to the stationary seat, and in which the inner locking portion of the locking member is retracted into the mounting hole and is disengaged from a respective one of the first locking grooves in the spindle coupling ring for unlocking the rotary seat from the spindle coupling ring. The rotary knob is operable to rotate the spindle for moving the deadbolt between the locking and unlocking positions when the locking members are disposed in the first position. An electric driving motor has a transmission shaft coupled to the gear plate portion of the rotary seat, and is operable to drive rotation of the rotary seat for moving the locking units to a second position, in which the outer locking portion of the locking member of each of the locking units slides past the respective one of the second locking grooves and is disengaged from the respective one of the second locking grooves for unlocking the rotary seat from the stationary seat, and in which the locking member is depressed by the inner peripheral surface of the ring portion of the stationary seat against restoring action thereof so as to enable the inner locking portion of the locking member to project from the inner surface of the clutch portion and engage the respective one of the first locking grooves in the spindle coupling ring for locking the rotary seat to the spindle coupling ring, thereby enabling co-rotation of the spindle for moving the dead bolt between the locking and unlocking positions. An electric switch unit is mounted in the lock housing, and is connected electrically to the electric driving motor. A switch actuator is mounted on the spindle for co-rotation therewith, and projects in a radial direction with respect to the axis of the spindle. The switch actuator is movable with the spindle relative to the electric switch unit, and enables the electric switch unit to control operation of the electric driving motor in a manner that the electric driving motor drives rotation of the spindle by a predetermined angle when the electric driving motor is operated.
The outer locking portion of each locking member has a head portion with a convex outer surface which slides past a tapered wall part in a respective one of the second locking grooves when the rotary seat is rotated for retracting the locking member into the respective mounting hole. It was found that sliding movement of the head portion of the locking member along the tapered wall part is slightly retarded by friction between the convex outer surface and the tapered wall part, thereby adversely affecting smooth movement during electrical operation of the electric door lock.
The object of the present invention is to provide an electric door lock that is operable both electrically and manually and that can be operated in a relatively smooth manner.
Accordingly, the electric door lock of the present invention includes a lock housing, a deadbolt mounted in the lock housing and movable between locking and unlocking positions, a manual operating member, a spindle coupling ring, a rotary seat, a stationary seat, a plurality of resilient locking units, an electric driving motor, an electric switch unit, and a switch actuator. The manual operating member is mounted on the lock housing, and has a deadbolt operating spindle that extends into the lock housing and that is connected operably to the deadbolt, and a manually operable rotary knob that is secured to one end of the spindle and that is disposed externally of the lock housing. The spindle coupling ring is sleeved on the spindle so as to be co-rotatable therewith. The spindle coupling ring has an annular outer peripheral surface formed with a plurality of first locking grooves. Each of the first locking grooves is displaced angularly from an adjacent one of the first locking grooves by a predetermined angle with respect to an axis of the spindle. The rotary seat has a circular gear plate portion that is sleeved rotatably on the spindle. The gear plate portion has a peripheral edge formed with a set of transmission teeth. The rotary seat further has an annular clutch portion connected fixedly and co-axially to the gear plate portion. The clutch portion is disposed around the spindle coupling ring, and has an inner surface confronting the spindle coupling ring, and an outer surface opposite to the inner surface. The clutch portion is formed with a plurality of mounting holes aligned respectively with the first locking grooves in the spindle coupling ring. Each of the mounting holes has an open inner hole end formed in the inner surface, and an open outer hole end formed in the outer surface. The stationary seat is disposed within and is secured to the lock housing. The stationary seat has a ring portion which is disposed around the clutch portion and which has an annular inner peripheral surface confronting the outer surface of the clutch portion. The inner peripheral surface is formed with a plurality of second locking grooves. Each of the second locking grooves is displaced angularly from an adjacent one of the second locking grooves by the predetermined angle with respect to the axis of the spindle. The locking units are mounted respectively in the mounting holes in the clutch portion. Each of the locking units includes a locking pin, a ball member, and a compression spring. The locking pin has an inner end disposed at the inner hole end of the respective one of the mounting holes, and an outer end opposite to the inner end and disposed proximate to the outer hole end of the respective one of the mounting holes. The ball member is disposed at the outer hole end of the respective one of the mounting holes adjacent to the outer end of the locking pin. The compression spring is disposed within the respective one of the mounting holes, and is sleeved around the locking pin for biasing the locking pin in a radial outward direction. The locking units are normally disposed in a first position, in which the ball members of the locking units project radially and outwardly relative to the outer surface of the clutch portion and engage respectively the second locking grooves in the stationary seat for locking the rotary seat to the stationary seat, and in which the inner ends of the locking pins are retracted into the mounting holes and are disengaged from the first locking grooves in the spindle coupling ring for unlocking the rotary seat from the spindle coupling ring. The rotary knob is operable to rotate the spindle for moving the deadbolt between the locking and unlocking positions when the locking units are disposed in the first position. The electric driving motor has a transmission shaft coupled to the transmission teeth of the rotary seat. The electric driving motor is operable to drive rotation of the rotary seat for moving the locking units to a second position, in which the ball members move rollingly out of the second locking grooves and move along the inner peripheral surface of the stationary seat so as to depress the locking pins in radial directions against restoring action of the compression springs and so as to enable the inner ends of the locking pins to project from the inner surface of the clutch portion and engage respectively the first locking grooves in the spindle coupling ring for locking the rotary seat to the spindle coupling ring, thereby enabling co-rotation of the spindle with the rotary seat for moving the deadbolt between the locking and unlocking positions. The electric switch unit is mounted in the lock housing, and is connected electrically to the electric driving motor. The switch actuator is mounted on the spindle for co-rotation therewith, and projects in a radial direction with respect to the axis of the spindle. The switch actuator is movable with the spindle relative to the electric switch unit, and enables the electric switch unit to control operation of the electric driving motor in a manner that the electric driving motor drives rotation of the spindle by the predetermined angle when the electric driving motor is operated.